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Biomedical subjects

V V Halbach

Publications and source records attributed to V V Halbach.

At least 73 records · Page 4Linked to original sources

Treatment of massive posterior epistaxis by detachable coil embolization of a cavernous internal carotid artery aneurysm.

We present a case of massive posterior epistaxis caused by a cavernous internal carotid artery aneurysm. This lesion was treated with endovascular placement of electrolytically detachable platinum embolization coils. The treatment resulted in cessation of epistaxis until the patient's death 3 months following embolization. We discuss aspects of using these above coils for this condition.

Aged↗

Spinal dural arteriovenous fistulas supplied by branches of the internal iliac arteries.

Spinal dural arteriovenous fistulas are abnormal arteriovenous connections on the surface of the dura. They are supplied by branches of intercostal, lumbar, vertebral, middle sacral, or subclavian arteries and rarely by branches of the internal iliac arteries. We present four cases of spinal dural arteriovenous fistulas supplied exclusively by branches of the internal iliac artery in which the clinical and magnetic resonance presentation were not suggestive of this unusual supply. In our experience, internal iliac artery supply was observed in 12.5% of cases of spinal dural arteriovenous fistulas. We recommend that selective internal iliac arteriography be included in the angiographic evaluation of patients suspected of having a spinal dural arteriovenous fistula.

Adult↗

Interventional neurovascular techniques in the treatment of stroke--state-of-the-art therapy.

Interventional neurovascular techniques for the treatment of patients presenting with symptoms of acute or impending stroke, are now being utilized with increasing frequency in three major areas. (i) For patients presenting with cerebrovascular ischaemic symptoms due to haemodynamically significant stenosis from atherosclerosis, vasculitis, intimal hyperplasia, and dissection, cerebral percutaneous transluminal angioplasty has been shown to be beneficial for both extracranial and intracranial disease. (ii) Patients with acute, embolic occlusion of the internal carotid, middle cerebral, distal vertebral, and basilar arteries have been successfully treated by placement of microcatheters directly into the thrombus with successful thrombolysis, recanalization, and reperfusion to the distal ischemic brain. (iii) Acute arterial vasospasm secondary to subarachnoid haemorrhage is now being managed by balloon angioplasty in those instances where conventional medical therapy has failed. These techniques are altering our current management and broadening the therapeutic alternatives for patients who present with acute cerebrovascular insufficiency and stroke in evolution. As wider experience is gained in these techniques, the clinical indications for their use will also broaden.

Adolescent↗

Thrombolytic therapy in acute stroke.

PURPOSE: To report the safety and efficacy of local, direct, intra-arterial and intravenous fibrinolysis treatment in selected cases of clinically symptomatic patients with acute occlusion of the intracranial cerebral arteries and dural sinuses. METHODS: Patients with acute progressive neurological deterioration, in spite of systemic anticoagulation and/or antiplatelet medications, presenting with occlusion of a major intracranial cerebral artery or dural sinus were tested. From a transfemoral approach through a guiding catheter, a 2.5F microcatheter was guided directly into the intracranial cerebral circulation and embedded within the clot. Infusion of urokinase was then performed directly into the thrombus until lysis was attained. RESULTS: In 36 total patients, 27 cases were treated for an acute arterial occlusion in 45 vascular territories. Clinically, there was neurological improvement in 18 (66.7%) cases. Complications directly related to therapy included symptomatic intracranial hemorrhage in three cases (11.1%), which included 1 case (3.7%) of vessel perforation. In 8 (29.6%) patients, there was no evidence of clinical improvement, and in long-term follow-up there were 9 (33.3%) patient deaths. Nine patients were treated for an intracerebral dural sinus thrombosis in ten vascular territories by local urokinase infusion. In 7 (77.8%) cases, there was angiographic evidence of clot lysis and clinical improvement of the patient's neurological condition. Minor complications including infection and noncerebral sites of bleeding occurred in 3 (33.3%) patients, requiring adjustment in urokinase infusion therapy. CONCLUSION: Local, direct intra-arterial or intravenous infusion of thrombolytic drugs for treatment of stroke patients may improve overall patient morbidity and mortality related to acute thromboembolic disease in the central nervous system. Further clinical studies are warranted to evaluate this form of therapy.

Acute Disease↗

Interventional neurovascular techniques for cerebral revascularization in the treatment of stroke.

Recent advances in interventional neurovascular radiology have altered the management of cerebrovascular diseases by providing alternative treatments in three areas. (1) Cerebral percutaneous transluminal angioplasty is being used more often as an alternative to surgical endarterectomy or bypass grafting for patients with high-grade vascular stenosis of the innominate, subclavian, carotid, vertebral, and intracranial blood vessels. To date, the success rate has been greater than 90%, with less than 10% morbidity. (2) Transluminal angioplasty and local infusion of antispasmodic drugs are being used to treat patients with severe angiographic vasospasm unresponsive to conventional medical therapy. Intracranial arterial vasospasm due to subarachnoid hemorrhage has remained a leading cause of delayed morbidity and mortality. Neurologic improvement, defined as improvement in the Hunt and Hess neurologic grading scale, has been shown in 60-80% of the patients so treated. (3) Local intraarterial fibrinolysis has been beneficial for patients with acute thromboembolic occlusion in both intracranial arteries and the cerebral dural sinuses. Preliminary studies indicate that early revascularization is associated with improved neurologic outcome. This review delineates the current state of the art in interventional neurovascular techniques for treating patients with stroke in evolution and patients with signs and symptoms of impending stroke due to vascular stenosis or occlusion. These techniques for cerebral revascularization are under investigation as potential life-saving therapy when conventional medical or surgical treatment has failed. As more experience is gained, the results of controlled clinical trials become available, and technical improvements evolve, these procedures will decrease the morbidity and mortality associated with strokes.

Angioplasty, Balloon↗

The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect.

Endovascular obliteration of intracranial aneurysms with preservation of the parent artery (endosaccular occlusion) has been advocated for patients who fail or are excluded from surgical clipping and cannot undergo Hunterian ligation therapy. To clarify the effect that endosaccular occlusion has on the presenting neurological signs, 26 patients with aneurysms and symptoms related to mass effect who underwent this therapy were followed for a mean of 60 months. Only patients with objective neurological deficits who had not suffered a hemorrhage were included in this series. Response to therapy was classified into one of three groups: "resolved," if the patient had complete resolution of presenting signs; "improved," if significant and sustained improvement was recorded in the neurological examinations, and "unchanged," if no change was observed. Thirteen patients (50%) were classified as resolved, 11 (42.3%) as improved, and two (7.7%) as unchanged. A comparison of patients classified as resolved with those who were improved revealed that the former group had less wall calcification (30% vs. 60%) and a shorter duration of symptoms. Patients with neurological sign resolution (62%) were more likely to have totally occluded aneurysms on late follow-up arteriograms than those who had improvement (28%) or were unchanged (0%). This study suggests that endosaccular embolization therapy can improve or alleviate presenting neurological signs unrelated to hemorrhage or distal embolization in the majority of cases.

Adolescent↗

Development of acquired arteriovenous fistulas in rats due to venous hypertension.

Dural sinus thrombosis has been hypothesized as a possible cause of dural arteriovenous fistulas (AVF's). The pathogenesis and evolution from thrombosis to actual development of an AVF are still unknown. To study dural fistula formation, a surgically induced venous hypertension model in rats was created by producing an arteriovenous shunt between the carotid artery and the external jugular vein. The external jugular vein beyond the anastomosis was ligated 2 to 3 months after surgery and angiography was performed to identify any new acquired AVF's. Forty-six male Sprague-Dawley rats, each weighing approximately 300 gm, were used for this study. In Group I, 22 rats underwent a common carotid artery anastomosis to the external jugular vein, which is the largest draining vein from the transverse sinus via the posterior facial vein, followed by proximal external jugular vein ligation. In Group II, 13 rats underwent the same surgical procedure, followed by contralateral posterior facial vein occlusion. Group III served as the control group, in which 11 rats underwent only unilateral external jugular vein occlusion with or without contralateral posterior facial vein occlusion. The shunts in Groups I and II were ligated at 2 to 3 months following surgery, and transfemoral angiography was performed immediately before and after occlusion. New acquired AVF's had developed in three rats (13.6%) in Group I, three rats (23.1%) in Group II, and no rats (0%) in Group III. One of these newly formed fistulas was located at the dural sinus, analogous to the human dural AVF. The other five were located in the subcutaneous tissue, including the face and neck. The dural AVF in the rat was present on follow-up angiography at 1 week after the bypass occlusion. It is concluded that chronic venous hypertension of 2 to 3 months' duration, without associated venous or sinus thrombosis, can induce new AVF's affecting the dural sinuses or the subcutaneous tissue.

Animals↗

Treatment of dural sinus thrombosis by urokinase infusion.

PURPOSE: To gain a preliminary understanding of the role of thrombolytic therapy for the thrombosed dural sinus, we retrospectively reviewed our initial experience. METHODS: Seven patients, ages 25 to 71, who presented with symptomatic dural sinus thrombosis and who failed a trial of medical therapy were treated with direct infusion of urokinase into the thrombosed sinus. Patients received urokinase doses ranging from 20,000 to 150,000 U/h with a mean infusion time of 163 hours (range 88 to 244 hours). RESULTS: Patency of the affected dural sinus was achieved with antegrade flow in all patients. Six patients either improved neurologically over their prethrombolysis state or were healthy after thrombolysis; one of them required angioplasty. The other patient improved after surgical repair of a residual dural arteriovenous fistula. The only complications were an infected femoral access site which resolved after treatment with antibiotics and hematuria which cleared after discontinuation of anticoagulation. CONCLUSIONS: Thrombolysis of the thrombosed dural sinus shows promise as a safe and efficacious treatment. The results of this study should provide the impetus for further research.

Adult↗

Intracranial aneurysms. Evolution and future role of endovascular techniques.

Treatment of patients with an intracranial aneurysm by interventional neurovascular techniques has made tremendous advances over the past decade. Innovative occlusion devices have included detachable latex and silicone balloons, liquid polymers, intravascular lasers, and stents. As this technology continues to evolve, treatment options will expand and morbidity will continue to decline. The indications for treatment using minimally invasive surgical techniques will alter current management for these difficult and challenging vascular disorders.

Animals↗

Recurrent ischemic events in two patients with painless vertebral artery dissection.

BACKGROUND AND PURPOSE: Vertebral artery dissection causes endothelial changes and stenosis that may lead to recurrent ischemic neurological events. The diagnosis may not be obvious because the dissection may be painless and "spontaneous" (no obvious trauma). Magnetic resonance angiography has increasingly been used to screen patients for this disorder, but its accuracy has not yet been established. CASE DESCRIPTION: Two patients were admitted with repeated transient ischemic attacks and strokes over 11 months and 1 month, respectively. Neither had a history of trauma, cervical pain, or headache. Magnetic resonance angiography failed to visualize vertebral artery dissections that were later revealed by conventional angiography. One patient's events were stopped by balloon occlusion of the vertebral artery proximal to the posterior inferior cerebellar artery branch. CONCLUSIONS: Magnetic resonance angiography is not yet sensitive enough to always visualize vertebral artery dissection. Vertebral artery dissection is a life-threatening condition that requires aggressive evaluation and treatment.

Adult↗

Treatment of giant intradural (perimedullary) arteriovenous fistulas.

Ten patients with giant intradural spinal arteriovenous fistulas (perimedullary Types II and III) were treated with embolization alone (three patients) or in combination with surgery (seven patients). Their ages at the time of treatment ranged from 2 to 40 years, with a mean of 19.5 years. The indications for treatment included progressive myelopathy in five patients, spinal subarachnoid hemorrhage in four, and acute paraplegia in one. Associated conditions included Rendu-Osler-Weber syndrome in two patients, and Cobb's syndrome in two patients. In one patient, the cause of the fistula may have been related to epidural anesthesia traumatizing a low tethered cord. Angiographically, the fistulas were subclassified in three groups: a single-hole fistula supplied by a single feeding medullary artery (three patients); a single-hole fistula supplied by multiple medullary arteries (three patients); and multiple separate fistulas supplied by multiple medullary arteries (four patients). Eight patients were classified as perimedullary Type III and two as perimedullary Type II. Embolic agents were delivered from transarterial routes in 14 procedures and transvenous routes in 2 procedures. A total of 16 embolizations and 8 operations were performed in 10 patients. Seven patients were cured of their fistula (as demonstrated by angiography), two patients had 5% residual filling and are scheduled for future therapy. One refused a follow-up angiographic examination. Complications related to embolization included rupture of the anterior spinal artery by a detachable balloon, resulting in transient worsening of paraplegia with recovery to baseline. Transient worsening of symptoms after surgery was common, but all patients returned to baseline or better. Dramatic improvement was observed in four patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Transluminal angioplasty for atherosclerotic disease of the vertebral and basilar arteries.

Transluminal angioplasty for hemodynamically significant stenosis (> 70%) involving the posterior cerebral circulation is now being performed by the authors in selected cases. A total of 42 lesions affecting the vertebral or basilar artery have been successfully treated by percutaneous transluminal angioplasty techniques in 41 patients. The lesions involved the proximal vertebral artery in 34 cases, the distal vertebral artery in five, and the basilar artery in three. Patients were examined clinically at 1 to 3 and 6 to 12 months after angioplasty. Three (7.1%) permanent complications occurred, consisting of stroke in two cases and vessel rupture in one. There were four (9.5%) transient complications (< 30 minutes): two cases of vessel spasm and two of cerebral ischemia. Clinical follow-up examination demonstrated improvement of symptoms in 39 cases (92.9%). Radiographic follow-up studies demonstrated three cases (7.1%) of restenosis involving the proximal vertebral artery; two were treated by repeat angioplasty without complication, and the third is being followed clinically while the patient remains asymptomatic. In patients with significant atherosclerotic stenosis involving the vertebral or basilar artery territories, transluminal angioplasty may be of significant benefit in alleviating symptoms and improving blood flow to the posterior cerebral circulation.

Adult↗

Grading venous restrictive disease in patients with dural arteriovenous fistulas of the transverse/sigmoid sinus.

Dural arteriovenous fistulas of the transverse/sigmoid sinus usually cause pulse-synchronous bruit but may present catastrophically. Current systems for classifying these vascular malformations do not consider obstruction of venous outflow, which increases the risk of intracranial hemorrhage due to retrograde flow via cortical veins. The authors have developed a grading system based on the severity of venous restrictive disease determined by superselective angiography. In a retrospective analysis of 25 patients with dural arteriovenous fistulas of the transverse/sigmoid sinus treated between 1988 and 1990, the grade of venous restrictive disease reflected the clinical presentation. Visual symptoms and central nervous system hemorrhage were more common in patients with cortical venous drainage and more severe distal venous occlusion (Grade 3: 31% and 31%, respectively; Grade 4: 67% and 100%, respectively) than in patients with cortical venous drainage and mild-to-moderate venous restrictive disease (Grade 2: 13% and 0%, respectively) or those without venous outflow (Grade 1: 0% and 0%, respectively). These preliminary results suggest that this grading system may be useful for predicting the risk of catastrophic clinical presentation and for guiding therapeutic decision-making in patients with dural arteriovenous fistulas of the transverse/sigmoid sinus. A prospective study of a larger number of patients is needed to validate the predictive value of this new grading system.

Adult↗

Endovascular treatment of vertebral artery dissections and pseudoaneurysms.

Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography. In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second). Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.

Adult↗